As a type of ancient eukaryote,Giardia lamblia has played a very important role in the process of biological evolution.Comparative genomics can reveal the evolutionary relationships of G.lambliaat the genetic level and further clarify the role of G.lambliain the process of biological evolution.This review describes the main research techniques used in comparative genomics and it describes the use of comparative genomics to study the biological evolution of G.lamblia.This review also discusses the prospects for using comparative genomics to study G.lamblia.